Hydraulic operating mechanism



Oct. 12, 1965 H. BURMESTER ETAL 3,211,852

HYDRAULIC OPERATING MECHANISM Filed July 27, 1962 United States Patent3,211,852 HYDRAULIC OPERATING MECHANISM Henry Bnrmester,Berlin-Mariendorf, and Paul Duffing,

deceased, late of Eerlin-Siemenstadt, Germany, by Monika Dufling andHildegard Dufiing, Berlin-Siemenstadt, and Lutz Dufling,Wuppertal-Barmen, Germany, heirs, assignors to Siemens SchuckertwerlreAlrtiengesellschaft, Erlangen, Germany, a corporation of Germany FiledJuly 27, 1962, Ser. No. 212,976

Claims priority, application Germany, July 27, 1961 5 Claims. (Cl.200-82) This invention relates to hydraulic operating mechanisms ingeneral and, more particularly to hydraulic operating mechanisms inwhich it is desired to retain the operating parts at an end positionregardless of leakage of the inlet valves.

A general object of the present invention is the provision of animproved hydraulic operating mechanism in which leakage of the inletvalves will not cause the operation mechanism to move to an opposite endposition after the mechanism has once reached a first position.

A further object of the present invention is the provision of animproved hydraulic operating mechanism particularly adapted for circuitbreaker use in which after the contact structure has either reached theopen or the closed circuit position, it is desirable to retain thecontact structure in the said position regardless of any leakage of theinlet valves.

Still a further object of the present invention is the provision of animproved simplified type hydraulic operating mechanism in which acontrol slide valve is interposed between the inlet valves and theoperating piston to assure that the operating piston will remain at oneof its two end positions regardless of any leakage of the inlet valves.

Although the invention will be particularly described as applied to ahigh voltage circuit interrupter, it will be apparent to those skilledin the art that the improved hydraulic drive of the present inventionmay be readily applied to other applications, other than circuit breakeruse, wherein it is desired to retain the operating parts at one of twoend positions regardless of any leakage of the inlet valves.

Further objects and advantages will readily become apparent upon readingthe following specification, taken in conjunction with the drawing, inwhich:

FIGS. 1A and 1B collectively illustrate an application of the inventionto a circuit breaker, the contact structure being illustrated in theopen circuit position.

Referring to the drawing, and more particularly to FIGS. 1A and 1Bthereof, the reference numeral 1 generally designates a hydraulicoperating mechanism including an accumulator 2, inlet valve structure 3,a control slide valve 5, an operating piston 6 and a sump 7. As shown,the operating piston 6 has a piston rod 6a associated therewith, whichis linked, as at 9, to a floating link 10 which operates a bell crank11. As shown in FIG. 1B, the operating bell crank 11 is pivotallymounted upon a stationary bracket 12 and has an operating arm 13associated therewith which effects the opening and closing movement of abridging contact 15. The bridging contact 15 makes separable engagementwith a spaced pair of stationary contacts 16 which control an electricalcircuit L L With reference to FIG. 1A, it will be noted that a pressureswitch 17 is provided to control the pressure within the high pressureaccumulator 2 and to effect energization of a compressor 18 which servesto withdraw fluid, such as oil, through a pipe line 20 from the3,211,852 Patented Oct. 12, 1965 sump 7 and compress it to the requisitehigh value through a check valve 21. Preferably there is not providedany gaseous region interiorly of the high pressure accumulator tank 2,and reliance is placed upon storing energy in the form of high-pressurehydraulic fluid, such as the oil 19.

A pair of inlet valves 22, 23 are provided having valve stems 22a, 23arespectively. The outer ends of the valve stems 22a, 23a may be engaged,in abutting fashion, by pivotally mounted actuating levers 24, 25 whichare pivotally mounted upon stationary brackets 26, 27. Toeffectoperative rotation of the actuating levers 24, 25 there may be providedelectromagnetic means, assuming in the illustrated form of the inventionan opening solenoid 28 and a closing solenoid 29. Thus, as more fullydescribed hereinafter, energization of the opening solenoid 28 willeffect through rotation of the actuating arm 25 opening of the inletvalve 23 and movement of the control slide valve 5 to the desiredposition to effect opening movement of the operating piston 6.Similarly, energization of the closing solenoid 29 will cause suitablerotation of the actuating lever 24 to effect opening of the inlet valve22 and positioning of the control slide valve 5 to the proper positionto effect rightward movement of the operating piston 6 and consequentclosing of the bridging contact 15 into engagement with the stationarycontacts 16.

It will be noted in connection with the operating piston 6 that bothsides thereof have fluid passages 30, 31 leading respectively to inletchambers 32, 33 which may be in communication with a sump pipe line 34,35 or with a high pressure inlet region 36. The high pressure inletregion 36, associated with the control slide valve 5, is in constantcommunication with an inlet manifold 37 which is supplied with highpressure hydraulic fluid 19 through opening of either of the inletvalves 22 or 23.

It will be observed that the control slide valve 5 has piston rodportions 5a, 5b which are pivotally connected, as at 50, 5d, with thelower extremities 24a, 25a of the actuating levers 24, 25. In addition,the control slide valve 5 has substantially equal-diameter valve spools5e and 5 with the inlet region 36 between the equal-diameter valvespools 5e and 5f. Fluid-passage means 4, comprising the inlet manifold37, the inlet region 36, and the fluid passages 30, 31, hydraulicallyinterconnect the inlet valves 22, 23 with both sides of the operatingpiston 6. The control valve 5 is interposed in said fluidpassage means 4between the inlet valves 22, 23 and the operating piston 6, with theinlet region 36 in constant communication with the fluid-passage means4.

It will also be noted that the operating piston 6 has an actuating arm40 secured to and movable therewith by means of the piston rod 6a. Alsoan additional arm 41 is secured to and movable with the operating piston6 by means of an additional piston rod 6b.

As shown in FIG. 1A, sump-passage means 8, comprising the sump pipelines 34, 35, is connected to the ends of the control valve 5 to theouter faces of the equal-diameter valve spools 52, 5f. Linkage means 14,comprising in the particular embodiment shown, the actuating levers 24,25, interconnects the control valve 5 with the inlet valves 22, 23,whereby motion of the control valve 5 effects opening of the inletvalves 22, 23, as more fully described hereinafter.

The improved hydraulic operating mechanism 1 functions in the followingmanner: When it is desired to move the circuit breaker contacts 15 tothe open circuit position, the control slide valve 5 is moved to thecorresponding position, either manually, or by electromagnetic means, asshown by energization of the opening solenoid 28. This will connect thefluid passage 31 to the inlet chamber 33 and will connect the inletchamber 32 with the sump pipe line 34. In addition, the counterclockwiserotation of the actuating lever 25 will effect throught the valve stem23a opening of the inlet valve 23 to permit high pressure oil 19 to flowfrom the accumulator 2 into the high pressure region 36 and through thefluid passage 31 to act upon the right-hand face of the operating piston6 to move the same in a leftward direction and effect opening of thecontact struc ture 15, 16.

At the extreme end of the opening stroke of the operating piston 6, theactuating arm 40 movable therewith will strike the right-hand end of thecontrol valve piston 5b and move the upper arm 25b away from theextremity of the valve piston 23a and permit the closing of the inletvalve 23. In this fully open circuit position of the interrupter it willbe observed that should either of the valves 22, 23 leak, neverthelessthe leakage of the high pressure oil will continue to act through thefluid passage 31 and on the right-hand face of the operating piston 6 toassure that the operating piston 6 will remain in its fully open circuitposition regardless of any leakage of the control valves 22, 23.

To effect the closing operation of the circuit breaker contacts 15, 16the closing solenoid 29 may be energized. This will mechanically forcethe actuating arm 24 in a clockwise direction about its pivot toforcibly bring the control piston 5 to the leftward position thereof,not shown, to open up the fluid passage 30 with the high pressure region36 and correspondingly effect opening of the inlet valve 22. The openingof the inlet Valve 22 will permit high pressure hydraulic fluid 19 fromthe accumulator 2 to pass through the high pressure inlet manifold 37,through the high pressure space 36 and through the fluid passage 30 toact upon the left-hand face of the operating piston 6 to effect closingof the contacts 15, 16. At the extreme right-hand end of the travel ofthe operating piston 6 the actuating arm 41 will strike the extremity ofthe piston stem 5a and forcibly cause counterclockwise rotative movementof the arm 24 to release the valve stem 22a and thereby effect closureof the inlet valve 22.

From the foregoing description of the invention it will be apparent thatby the provision of the control slide valve 5 interposed between theinlet valves 22, 23 and the working piston 6 regardless of anyleakage ofthe inlet valves 22, 23 the disposition of the control valve 5 will besuch as to constantly apply any pressure upon the proper face of theworking piston 6 to maintain the piston 6 in its end position.

It will be apparent that for certain applications the electromagneticsolenoids 28, 29 may be omitted and merely a manual operation of theactuating levers 24 ,25 resorted to.

' In other words, the initiating means 46, for initiating operation ofthe hydraulic drive 1, may comprise the electromagnetic solenoid 28, 29shown in FIG. 1A, or manual means (not shown), and effects motion of thecontrol valve 5 to set into operation the sequence of events to resultin the movement of the operating piston 6 to either one of its twooperating positions.

In addition, although there has been described two valves 22, 23 in aparticular construction shown, nevertheless a single valve may besufficient because in effect the two valves 22, 23 are arranged inparallel. In such an eventuality, that is using a single valve, theremust be a provision made to the effect that this single valve may beclosed at the end position of the operating piston 6.

To provide a dashpot action toward the end of the movements of theoperating piston 6 preferably enlarged portions 60, 6d may be providedcooperating with restrictions 44, 45 to effect dashpot action at theends of the travel of the operating piston 6.

Although there has been illustrated and described a specific structure,it is to be clearly understood that the same was merely for the purposeof illustration, and that changes and modifications may readily be madetherein by those skilled in the art without departing from the spiritand scope of the invention.

We claim as our invention:

1. A hydraulic drive including at least one inlet valve and an operatingpiston, fluid-passage means interconnecting the inlet valve with bothsides of the operating piston, a control valve with equal-diameter valvespools having an inlet region between said equal-diameter valve spoolsin constant communication with said fluid-passage means said controlvalve interposed in said fluid-passage means between said one inletvalve and the operating piston, sump-passage means connected to the endsof the control valve to the outer faces of said equal-diameter valvespools, linkage means interconnecting said control valve with said oneinlet valve, whereby motion of said control valve effects opening ofsaid inlet valve, and means initiating movement of the hydraulic driveby effecting motion of said control valve.

2. A hydraulic drive including a pair of inlet valves and an operatingpiston, fluid-passage means interconnecting the inlet valves with bothsides of the operating piston, a control valve with equal-diameter valvespools having an inlet region between said equal-diameter valve spoolsin constant communication with said fluid passage means, said controlvalve interposed in said fluid passage means between said inlet valvesand the operating piston, sump-passage means connected to the ends ofthe control valve to the outer faces of said equal-diameter valvespools, linkage means interconnecting said control valve with said inletvalves, whereby motion of said control valve effects opening of saidinlet valves, and means initiating movement of the hydraulic drive byeffecting motion of said control valve.

3. A hydraulically-operated circuit breaker including separable contactmeans, a hydraulic drive for the circuit breaker including at least oneinlet valve and an operating piston, means connecting the operatingpiston to the separable contact means to effect opening and closingmovement thereof, fluid passage means interconnecting the inlet valvewith both sides of the operating piston, a control valve with aequal-diameter valve spools having an inlet region between saidequal-diameter valve spools in constant communication with said fluidpassage means, said control valve interposed in said fluid passage meansbetween said one inlet valve and the operating piston, sump passagemeans connected to the ends of the control valve to the outer faces ofsaid equal-diameter valve spools, linkage means interconnecting saidcontrol valve with said one inlet valve, whereby motion of said controlvalve effects opening of said inlet valve, and means initiating movementof the hydraulic drive by effecting motion of said control valve.

4. A hydraulic drive including at least one inlet valve and an operatingpiston, fluid-passage means interconnecting the inlet valve with bothsides of the operating piston, a control valve with equal-diameter valvespools having an inlet region between said equal-diameter valve spoolsin constant communication with said fluid passage means, said controlvalve interposed in said fluid-passage means between said one inletvalve and the operating piston, sump passage means connected to the endsof the control valve to the outer faces of said equal-diameter valvespools, linkage means interconnecting said control valve with said oneinlet valve, whereby motion of said control valve effects opening ofsaid inlet valve, means initiating movement of the hydraulic drive byeffecting motion of said control valve, and means movable in response tomotion of said operating piston to effect closure of'said one inletvalve.

5. A hydraulically-operated circuit breaker including separable contactmeans, a hydraulic drive for said circuit breaker including at least oneinlet valve and an operating piston, means connecting the operatingpiston to the separable contact means to efiect opening and closingmovement thereof, fluid-passage means interconnecting the inlet valvewith both sides of the operating piston, a control valve withequal-diameter valve spools having an inlet region between saidequal-diameter valve spools in constant communication with said fluidpassage means, said control valve interposed in said fluid-passage meansbetween said one inlet valve and the operating piston, sump passagemeans connected to the ends of the control valve to the outer faces ofsaid equal-diameter valve spools, linkage means interconnecting saidcontrol valve with said one inlet valve, whereby motion of said controlvalve effects opening of said inlet valve, means initiating ReferencesCited by the Examiner UNITED STATES PATENTS 2,523,572 9/50 Jansson200-82 2,730,589 1/56 Perry et a]. 20082 2,736,295 2/56 Peek ZOO-822,920,170 1/60 Caswell 200-82 BERNARD A. GILHEANY, Primary Examiner.

1. A HYDRAULIC DRIVE INCLUDING AT LEAST ONE INLET VALVE AND AN OPERATINGPISTON, FLUID-PASSAGE MEANS INTERCONNECTING THE INLET VALVE WITH BOTHSIDES OF THE OPERATING PISTON, A CONTROL VALVE WITH EQUAL-DIAMETER VALVESPOOLS HAVING AN INLET REGION BETWEEN SAID EQUAL-DIAMETER VALVE SPOOLSIN CONSTANT COMMUNICATION WITH SAID FLUID-PASSAGE MEANS SAID CONTROLVALVE INTERPOSED IN SAID FLUID-PASSAGE MEANS BETWEEN SAID ONE INLETVALVE AND THE OPERATING PISTON, SUMP-PASSAGE MEANS CONNECED TO THE ENDSOF THE CONTROL VALVE TO THE OUTER FACES OF SAID EQUAL-DIAMETER VALVESPOOLS, LINKAGE MEANS INTERCONNECTING SAID CONTROL VALVE WITH SAID ONEINLET VALVE, WHEREBY MOTION OF SAID CONTROL VALVE EFFECTS OPENING OFSAID INLET VALVE, AND MEANS INITIATING MOVEMENT OF THE HYDRAULIC DRIVEBY EFFECTING MOTION OF SAID CONTROL VALVE.